Foodborne illness

Foodborne illness or food poisoning is caused by consuming food contaminated with pathogenic bacteria, toxins, viruses, prions or parasites. Such contamination usually arises from improper handling, preparation or storage of food. Foodborne illness can also be caused by adding pesticides or medicines to food, or by accidentally consuming naturally poisonous substances like poisonous mushrooms or reef fish. Contact between food and pests, especially flies, rodents and cockroaches, is a further cause of contamination of food.

Pathogenic agents

An early theory on the causes of food poisoning involved ptomaines, alkaloids found in decaying animal and vegetable matter. While some poisonous alkaloids are the cause of poisoning, the discovery of bacteria left the ptomaine theory obsolete.

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

Bacteria

Bacterial infection is the most common cause of food poisoning. In the United Kingdom during 2000 the individual bacteria involved were as follows: Campylobacter jejuni 77.3%, Salmonella 20.9%, ' 1.4%, and all others less than 0.1% http://www.food.gov.uk/science/sciencetopics/microbiology/58736.

Related Topics:
Bacteria - United Kingdom - 2000 - Campylobacter jejuni - Salmonella

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

Symptoms for bacterial infections are delayed because the bacteria need time to multiply. They are usually not seen until 12-36 hours after eating contaminated food.

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

Common bacterial foodborne pathogens are:

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

• Aeromonas hydrophila, Aeromonas caviae, Aeromonas sobria
• Bacillus cereus
• Brucella spp.
• Campylobacter jejuni which causes Guillain-Barré syndrome
• Corynebacterium ulcerans
• Coxiella burnetii or Q fever
• ' enterohemorrhagic (EHEC) which causes hemolytic-uremic syndrome
• Escherichia coli - enteroinvasive (EIEC)
• Escherichia coli - enteropathogenic (EPEC)
• Escherichia coli - enterotoxigenic (ETEC)
• Escherichia coli - enteroaggregative (EAEC or EAgEC)
• Listeria monocytogenes
• Plesiomonas shigelloides
• Salmonella spp.
• Shigella spp.
• Streptococcus
• Vibrio cholerae, including O1 and non-O1
• Vibrio parahaemolyticus
• Vibrio vulnificus
• Yersinia enterocolitica and Yersinia pseudotuberculosis

Exotoxins

In addition to disease caused by direct bacterial infection, some foodborne illnesses are caused by exotoxins which are excreted by the cell as the bacterium grows. Exotoxins can produce illness even when the microbes that produced them have been killed. Symptoms typically appear after 1-6 hours depending on the amount of toxin ingested.

Related Topics:
Exotoxin - Excreted

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

• Clostridium botulinum
• Clostridium perfringens
• Staphylococcus aureus

For example Staphylococcus aureus produces a toxin that causes intense vomiting. The rare but potentially deadly disease botulism occurs when the anaerobic bacterium Clostridium botulinum grows in improperly canned low-acid foods and produces a powerful paralytic toxin.

Related Topics:
Staphylococcus aureus - Vomiting - Botulism - Anaerobic - Clostridium botulinum

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

Preventing bacterial food poisoning

The prevention is mainly the role of the state, through the definition of strict rules of hygiene and a public service of veterinary survey of the food chain, from farming to the transformation industry and the delivery (shops and restaurants). This regulation includes:

Related Topics:
Hygiene - Public service - Veterinary - Farming - Restaurant

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

• traceability: in a final product, it must be possible to know the origin of the ingredients (originating farm, identification of the harvesting or of the animal) and where and when it was processed; the origin of the illness can thus be tracked and solved (and possibly penalized), and the final products can be removed from the sale if a problem is detected;
• respect of hygiene procedures like HACCP and the "cold chain";
• power of control and of law enforcement of the veterinarians.

At home, the prevention mainly consists of:

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

• seperating foods while preparing and storing to prevent cross contamination. (i.e. clean cutting boards, utensils, and hands after handling meat and before cutting vegetables, etc.)Wash hands and/or gloves before handling ready-to-eat foods.
• the respect of the food storage (hot foods hot and cold foods cold) and food preservation methods (especially refrigeration), and checking the expiration date;
• washing the hands before preparing the meal and before eating;
• washing the fresh fruits and vegetables with clear water, especially when not cooked (e.g. fruits, salads)Scrub firm fruits and vegetables with a brush to clean.;
• washing the dishes after use;
• keeping the kitchen and cooking utensils clean.

Bacteria need warmth, moisture, food and time to grow. The presence, or absence, of oxygen, salt, sugar and acidity are also important factors for growth. In the right conditions, one bacterium can multiply using binary fission to become four million in eight hours. Since bacteria can be neither smelled nor seen, the best way to ensure that food is safe is to follow principles of good food hygiene. This includes not allowing raw or partially cooked food to touch dishes, utensils, hands or work surfaces previously used to handle even properly cooked or ready to eat food.

Related Topics:
Warmth - Moisture - Time - Grow - Oxygen - Salt - Sugar - Acid - Binary fission - Million - Smell - Seen - Hygiene - Raw - Hand

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

High salt, high sugar or high acid levels keep bacteria from growing, which is why salted meats, jam, and pickled vegetables are traditional preserved foods.

Related Topics:
Jam - Pickle

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

The most frequent causes of bacterial foodborne illnesses are cross-contamination and inadequate temperature control. Therefore control of these two matters is especially important.

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

Thoroughly cooking food until it is piping hot, i.e. above 70 °C (158 °F) will quickly kill virtually all bacteria, parasites or viruses, except for Clostridium botulinum and Clostridium perfringens, which produces a heat-resistant spore that survives temperatures up to 100 °C (212 °F). Once cooked, hot foods should be kept at temperatures out of the danger zone. Temperatures above 63 °C (145 °F) stop microbial growth.

Related Topics:
Cooking - Clostridium botulinum - Clostridium perfringens - Spore - Danger zone

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

Cold foods should also be kept colder than the danger zone, below 5 °C (41 °F). However, Listeria monocytogenes and Yersinia enterocolitica can both grow at refrigerator temperatures.

Related Topics:
Listeria monocytogenes - Yersinia enterocolitica - Refrigerator

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

Viruses

Viral infections make up perhaps one third of cases of food poisoning in developed countries. They are usually of intermediate (1-3 days) incubation period, cause illnesses which are self-limited in otherwise healthy individuals, and are similar to the bacterial forms described above.

Related Topics:
Viral - Incubation period

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

• Norovirus (formerly Norwalk virus)
• Rotavirus
• Hepatitis A is distinguished from other viral causes by its prolonged (2-6 week) incubation period and its ability to spread beyond the stomach and intestines, into the liver. It often induces jaundice, or yellowing of the skin, and rarely leads to chronic liver dysfunction.
• Hepatitis E

Parasites

Most foodborne parasites are zoonoses.

Related Topics:
Parasite - Zoonoses

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

Platyhelminthes:

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

• Taenia saginata
• Taenia solium
• Fasciola hepatica

See also: Tapeworm

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

Nematode:

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

• Ascaris lumbricoides
• Trichinella spiralis
• Trichuris trichiura

Protozoa:

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

• Acanthamoeba and other free-living amoebae
• Cryptosporidium parvum
• Entamoeba histolytica
• Giardia lamblia
• Sarcocystis hominis
• Sarcocystis suihominis
• Toxoplasma gondii

Other:

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

• Anisakis sp.
• Cyclospora cayetanensis
• Diphyllobothrium sp.
• Eustrongylides sp.
• Nanophyetus sp.

Natural toxins

In contrast several foods can naturally contain toxins that are not produced by bacteria and occur naturally in foods, these include:

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

• Aflatoxin
• Alkaloid, see hemlock
• Ciguatera poisoning
• Grayanotoxin (honey intoxication)
• Mushroom toxins
• Phytohaemagglutinin (Red kidney bean poisoning)
• Pyrrolizidine alkaloid
• Shellfish toxin, including Paralytic shellfish poisoning, Diarrhetic shellfish poisoning, Neurotoxic shellfish poisoning, Amnesic shellfish poisoning and Ciguatera fish poisoning
• Scombrotoxin
• Tetrodotoxin (Fugu fish poisoning)

Other pathogenic agents

• Prions, resulting in Creutzfeldt-Jakob disease